{"id":47900,"date":"2025-05-30T15:53:19","date_gmt":"2025-05-30T19:53:19","guid":{"rendered":"https:\/\/mjtsai.com\/blog\/?p=47900"},"modified":"2025-06-06T17:01:07","modified_gmt":"2025-06-06T21:01:07","slug":"xcode-16-4","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2025\/05\/30\/xcode-16-4\/","title":{"rendered":"Xcode 16.4"},"content":{"rendered":"<p><a href=\"https:\/\/developer.apple.com\/documentation\/xcode-release-notes\/xcode-16_4-release-notes\">Apple<\/a> (<a href=\"https:\/\/developer.apple.com\/download\/all\/\">downloads<\/a>):<\/p>\n<blockquote cite=\"https:\/\/developer.apple.com\/documentation\/xcode-release-notes\/xcode-16_4-release-notes\"><p>Fixed: Users may see excessive CPU utilization from diskimagesiod which reduces simulator performance, increasing boot time, process launch times, and test execution times.<\/p><p>[&#8230;]<\/p><p>The command <code>devicectl diagnose<\/code> now obtains a sysdiagnose from your Mac and all available devices by default.<\/p><p>[&#8230;]<\/p><p>Fixed: <code>NSURLSession<\/code> was always timing out and failing in iOS 18.3 simulator runtimes.<\/p><p>Fixed: Some C++ headers were experiencing crashes in syntax highlighting and Quick Help.<\/p><\/blockquote>\n\n<p>Not a lot of changes here. It seems to be working the same as Xcode 16.3 for me&mdash;no new problems, but it doesn&rsquo;t seem to fix all the issues introduced in 16.x, either.<\/p>\n\n<p><a href=\"https:\/\/mastodon.social\/@troz\/114593613045398655\">Sarah Reichelt<\/a>:<\/p>\n<blockquote cite=\"https:\/\/mastodon.social\/@troz\/114593613045398655\"><p>I see some people reporting problems with Xcode 16.4 but it solved a problem for me. I was holding off the pre-release of my book &ldquo;Escape from Tutorial Hell&rdquo; because 16.3 had a bug that crashed a playground the used JSON decoding. So please don&rsquo;t try to use Xcode 16.3 with any playground in the book. 16.2 and 16.4 are both fine.<\/p><\/blockquote>\n\n<p>Previously:<\/p>\n<ul>\n<li><a href=\"https:\/\/mjtsai.com\/blog\/2025\/04\/01\/xcode-16-3\/\">Xcode 16.3<\/a><\/li>\n<\/ul>\n\n<p id=\"xcode-16-4-update-2025-06-03\">Update (<a href=\"#xcode-16-4-update-2025-06-03\">2025-06-03<\/a>): <a href=\"https:\/\/mastodon.social\/@quicheindustries\/114599709824599660\">Quiche Industries<\/a>:<\/p>\n<blockquote cite=\"https:\/\/mastodon.social\/@quicheindustries\/114599709824599660\"><p>There&rsquo;s a <a href=\"https:\/\/mastodon.social\/@xmollv\/114590660681750942\">huge<\/a> <a href=\"https:\/\/developer.apple.com\/forums\/thread\/785964\">regression<\/a> preventing testing WebKit apps in simulator with Xcode 16.4 and deployment target set under iOS 18.4.<\/p><\/blockquote>\n\n<p id=\"xcode-16-4-update-2025-06-06\">Update (<a href=\"#xcode-16-4-update-2025-06-06\">2025-06-06<\/a>): <a href=\"https:\/\/fatbobman.com\/en\/snippet\/speed-up-compilation-with-prebuilt-swift-syntax\/\">Fatbobman<\/a>:<\/p>\n<blockquote cite=\"https:\/\/fatbobman.com\/en\/snippet\/speed-up-compilation-with-prebuilt-swift-syntax\/\">\n<p>Starting with Swift 6.1.1 and Xcode 16.4, you can dramatically reduce build times for macro projects by enabling prebuilt SwiftSyntax. Use Xcode defaults or the <code>--enable-experimental-prebuilts<\/code> flag in command-line builds to skip rebuilding SwiftSyntax from source. Clear existing build caches before first use for best results.<\/p>\n<\/blockquote>","protected":false},"excerpt":{"rendered":"<p>Apple (downloads): Fixed: Users may see excessive CPU utilization from diskimagesiod which reduces simulator performance, increasing boot time, process launch times, and test execution times.[&#8230;]The command devicectl diagnose now obtains a sysdiagnose from your Mac and all available devices by default.[&#8230;]Fixed: NSURLSession was always timing out and failing in iOS 18.3 simulator runtimes.Fixed: Some C++ [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"apple_news_api_created_at":"2025-05-30T19:53:22Z","apple_news_api_id":"2d087b86-30ff-47ba-a568-bc130c585234","apple_news_api_modified_at":"2025-06-06T21:01:10Z","apple_news_api_revision":"AAAAAAAAAAAAAAAAAAAAAQ==","apple_news_api_share_url":"https:\/\/apple.news\/ALQh7hjD_R7qlaLwTDFhSNA","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_is_hidden":false,"apple_news_is_paid":false,"apple_news_is_preview":false,"apple_news_is_sponsored":false,"apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":"\"\"","apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"footnotes":""},"categories":[2],"tags":[326,30,2598,941,71,1959,901,226],"class_list":["post-47900","post","type-post","status-publish","format-standard","hentry","category-technology","tag-c-plus-plus","tag-mac","tag-macos-15-sequoia","tag-macros","tag-programming","tag-simulator","tag-swift-programming-language","tag-xcode"],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/47900","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/comments?post=47900"}],"version-history":[{"count":3,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/47900\/revisions"}],"predecessor-version":[{"id":47985,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/47900\/revisions\/47985"}],"wp:attachment":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/media?parent=47900"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/categories?post=47900"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/tags?post=47900"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}